Industrial gear pump



May 17, 1966 H. H. scHMlEL ETAL 3,251,309

INDUSTRIAL GEAR PUMP Filed April 12, 1963 7 Sheets-Sheet 1 L w Q n 0 n Q i M m #a Y# wmwwf N N u May 17, 1966 H. H. scHMlEl. ETAL 3,251,309

INDUSTRIAL GEAR PUMP '7 Sheets-Sheet 2 Filed April l2, 1963 ATTORNEYS INDUSTRIAL GEAR PUMP Filed April 12, 1963 7 Sheets-Sheet 3 ATTORNEYS May 17, 1966 H. H. Scl-*MIEL Em. 3,251,309

INDUSTRIAL GEAR PUMP 7 Sheets-Sheet 4 Filed April l2, 1965 l WMF May 17, 1966 H. H. scHMn-:L ETAL 3,251,309

INDUSTRIAL GEAR PUMP Filed April l2, 1963 '7 Sheets-Sheet 5 ii" BY ATTORNEYS May 17,1966 H. H. scHMlEL. ETAL 3,251,309

INDUSTRIAL GEAR PUMP 7 Sheets-Sheet 6 Filed April 12, 1963 m OrF m-.HM MM@ MMR .e EEE Ew V: www. v s. m mw HZ mm m n w .www mw .m Enm dmv Nn@ #e W v 4 www w \M mw Itm" Q @HH mv mq 1 wwf mx mmm mm\ ww AQ May 17, 1966 Y H. H. scHMlEl. ETAL 3,251,309

INDUSTRIAL GEAR. PUMP Filed April l2, 1963 7 Sheets-Sheet 7 2F16. I4 @E IFJGJS INVENTORS HEQBEQT I-LSCHMIEL.

WMVMHNMXM ATTORNEYS United States Patent Office 21251309A Patented May 17, 1966 3,251,399 INDUSTRIAL GEAR PUMP Herbert H. Schmiel, Willoughby, and Alvin L. Zander,

Maple Heights, Ohio, assignors to Parker-Hanniiiu Corporation, Cleveland, Ohio v Filed Apr. 12, 1963, Ser. No. 273,802 26 Claims. (Cl. 10S-126) This application is a continuation-impart of our lapplication Serial No. 851,389, iiled November 6, 1959, now abandoned.

Common forms of rotary pumps have two meshed gears operable within a pumping chamber for pumping fluid from a receiving zone connected with a supply conduit, to a delivery zone connected with a delivery conduit. In such pumps, the fluid pressure is relatively low at the receiving side of the pump but lso increases toward the delivery side that it will separate the opposed side walls of the pumping chamber from sealing contact with the side faces of the gears, if not yadequately counteracted.

Various proposals have been made for applying fluid pressure generated by the pump to pistons or the like in such a manner as to counteract the separating force exerted on the pumping chamber side walls but such proposals have not completly solved the problem. This has-been due, to a -large extent to the fact that the pres sure tending to separate the pumping chamber side Walls from the gears has not been consistently exterted upon such definite and constant areas yof said 4side walls .as to give any concrete basis for determining the extent of the areas to which pump pressure mrust be applied for elective counteraction.

The present invention aims to overcome the above ditiiculty by providing the inner sides of the pumping chamber side walls with arcuate grooves substantially concentric with the gears, radially spanned by the gear teeth, and extending from points between the lluid receiving and delivery zones substantially to the meshing zone of the gears, and by providing said side walls with passages which place said grooves in communication with said delivery zone. 'Ihe grooves thus provide the side walls with definite and constant areas against which the wall separating pressurel is applied and consequently provide Ia concrete basis for ruse in determining the extent of the areas to which thepressure of the delivered uid should be applied for effective counteraction of said separating pressure.

Another object has been to provide a novel'pump co struction in which the pumping chamber side walls are formed by substantial Wear plates backed by bearing blocks which are instrumental in mounting the gears, and in which two pistons mounted in one end closure of the pump housing, act against two of said bearing blocks, respectively, to hold the bearing blocks, wear plates and gears in contact with each other.

A further object is to provide the wearY plates with the aforesaid arcuate grooves and the aforesaid passages, to thereby give said wear plates definite and constant areas subjected to `delivered iiuid pressure, and to offset the axes of the aforesaid pistons toward the delivery side of the pump to concentrate the force exerted by said pistons where most needed.

A further object of this invention is to provide a novel wear plate which is of a one piece construction as opposed to the previous two-piece construction wherein a much 'greater strength is obtained and the previous possible slippage of wear plate halves relative to one another is eliminated.

Another object of this invention is to provide a novel bearing block and seal combination wherein the bearing blocks and lseal are reversible.

Still another object of this invention is to provide a novel method of assembling bearing blocks Within a pump housing, the method including the steps of assembling ltwo 'bearing blocks and a seal into a composite unit and then indiscriminately placing the bearing block and seal unit into the pump housing.

Yet another object of this invention is to provide a novel seal for positioning between two bearing blocks, the seal being of a reversible construction wherein it may' be indiscriminately mounted between two bearing blocks Without regard as to orientation.

A Ifurther object of this invention is to provide in a pump pressure assembly for applying pressures to bearing blocks and wear plates utilizing pistons, wherein the pistons are offset and the pressure is applied to the bearing blocks Ifrom the pistons through large pressure transmitting plates.

Another object is to provide for effective sealing against leakage betwen the bearing Vblocks and the walls of housing bores in which they are received, and to seal both transversely and longitudinally between abutting surfaces of said bearing blocks.

Yet another object is to provide a novel construction which may be expeditiously manufactured, profitably marketed at a reasonable price, and capablevof giving maximum troubleree service.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a longitudinal sectional view on line 1 1 of FIGURE 4.

FIGURE 2 is an end view, partly in section, on line 2 2 of FIGURE 1.

FIGURE` 3 is a transverse sectional view on line 3 3 of FIGURE l.

FIGURE 4 is a horizontal sectional view on line 4 4 of FIGURE 1.

FIGURE 5 is a side elevation of one set of the wear plates.

FIGURE 6 is a detail sectional view on line 6 6 of FIGURE 5.

IIGURE 7 is a side view of one of the 8-shaped O-ring sea s.

FIGURE 8 is a sectional view, partly in elevation, on line 8 8 of FIGURE 7. l

FIGURE 9 is a side View of one of the bearing blocks.

FIGURE9a is a side view of .another of the bearing blocks.

sectional View similar to FIGURE 1 and shows a modii iied form of wear plate and pressure piston arrangement.

FIGURE 11 is a perspective view of a modified form of wear plate.

FIGURE l2 4is a sectional view taken through the wear plate of FIGURE l1 Ialong the line 12 12 and shows a partial cross section thereof.

FIGURE 13 is a sectional view taken through the wear plate of FIGURE ll along the line 13 13 and shows a partial cross section thereof.

FIGURE 14 is `a longitudinal sectional view similar to FIGUREIO and shows a modified for-m of bearing block and seal assembly within the pump housing.

FIGURE l5 is a perspective view of a modified form of seal.

FIGURE 16 is a fragmentary schematic perspective view showing a bearing block and seal assembly being,

positioned within the pump housing.

The construction shown in the drawings will be rather specifically described but attention is invited to the possibility of making variations.

A pump housing is formed from a body 11 and end closures 12 and 13 secured to said ybody by screws 14. O-ring gaskets 15 seal between the end closures 12, 13 and the body 11. The end closure 12 is formed with a hollow boss 16 containing bearings 17 for a drive shaft 18: and a cap plate 19 is secured to said boss and cont-ains a suitable seal 2i? -for said shaft. The outer end of the `shaift 18 is provided with a splined head 21 for connecting it with a driving means: and the cap plate 19 may well constitute a mounting plate instrumental in securing the housing 10 in fixed relation with said driving means. The inner end of the shaft 18 has spline ribs 22 for engagement with one of the meshed pumping gears later described.

The body 11 is formed with two longitudinal cylindrical bores 23 and 23a which intersect at a median plane P (FIGURES 2 and 3). In FIGURE 3, a second plane P has been indicated extending diametrically' through the longitudinal centers C of the bores 23 and 23a. At one side of this plane P', the body 11 has an internal recess 24 which opens through the walls of the bores 23 and 23a and provides a receiving zone R for the fluid to be pumped. At the opposite side of the plane P', the body 11 has another recess 25 which also opens through the walls of the bores 23 and 23a and provides a delivery zone D to which the pump gears deliver the uid from the receiving zone R; The zone R has an inlet 26 lfor connection with a uid inlet conduit: and the zone D has an outlet 27 'for connection with a fluid delivery conduit.

One set of bearing blocks 28, 28a (FIGURE 1) is provided `at one end of the body 11: and a second set of bearing blocks 29, 29a is provided Aat the other end of said body 11. The blocks 28 and 29 are in the ends of the bore 23 and conform thereto: and the blocks 28a and 29a are in the ends of the bore 23a and conform thereto. The blocks 28, 28a of the first set solidly abut the end closure 12: and the blocks 29, 29a of the second set are substantially in contact with the inner side of the end closure 13. The closure 12 is preferably recessed somewhat at 38 (FIGURE 1) to receive the outer ends of the blocks 28 and 28a. These blocks 28, 28a have flat surfaces 31 which abut at the median plane P: and the blocks 29, 29a also have such surfaces 32 which abut at said plane P. All of the blocks 28, 28a, 29 and 29a are identical for ease of manufacture `and assembly: and novel sealing means is associated with said blocks -as hereinafter described.

Wear plates 33 and 33a, of the first set, contact with the inner sides of the bearing blocks 28 and 28a, respectively, and have straight edges 34 which abut -at the median plane P. Other wear plates 35 and 35a, of a second set, contact with the inner sides of the bearing blocks 29 and 29a, respectively, and have straight edges 36 which abut at the median plane P. All of the wear plates 33, 33a, 35 and 35a peripherally conform to the bores 23, 23a, except in the region of the uid receiving zone R. In this region, said wear plates are notched at 37 (FIG- URES 3, 4 and 5) to allow end filling as well as radial filling of the between-teeth pockets of the pumping gears.

As seen in FIGURES 3 and 5, each of the wear plates 33, 33a, 35 and 35a has a central openin7 38, an arcuate groove 39 concentric with said opening, and another groove 40 from said arcuate groove 39 to the peripheral edge of the plate. Both grooves 39, 46 open through the inner side farce of `the wear plate. The groove 39 extends from a point 39a (FIGURE 3) about midway between the receiving zone R and the delivery zone D, to a point 39h in the zone in which the pumping gears mesh: and the radial `groove 40 is in direct communication with said delivery zone D. The grooves function as later described.

One pumping gear 41 is interposed between the two wear plates 33 and 35 and has its side faces in sealing contact with the inner side faces o-f said wear plates. Another pumping gear 41a is interposed between the two wear plates 33a and 35a and has its side 'faces in sealing contact with the inner side faces olf these wear plates. The two gears mesh across the median plane P, as seen in FIGURE 3, and their teeth radiallyA span the wear plate grooves `39.

Each gear 41, 41a has tubular bearing stubs 42 extending through the wear plate openings 38 and mounted in roller bearings 43 within the bearing blocks 28, 28a, 29 and 29a. Each gear has internal spline ribs 44 engageable with the ribs 22 of the drive shaft 18. The gear 41 is engaged with the drive shaft if the latter rotates in the proper direction to operate the pump. Otherwise, the drive shaft must drive the gear 41a and this necessitates that the housing body 11, end closure 13 and elements within be turned with respect to the end closure 12. Such procedure, however, is not novel.

Due to the wear plates grooves 39 which communicate through the grooves 40 with the delivery zone D, the portions of the wear plates at 4the delivery side of the pump are each provided with a constant area which is consistently subjected to the pressure of the delivered fluid. This pressure tends to separate the wear plates from the gears at the delivery side of the pump but due to the constant areas against which said pressure acts, it is possible to provide effective means for counteracting it and thus preventing such separation of the wear plates from the gears. The pressure at the fluid receiving side of the pump is relatively low and :has no appreciable separating effect upon the wear plates.

Two pistons 45 and 45a (FIGURES l, 2 and 3) are mounted in recesses 46 and 46a for-med in the end closure 13 and said pistons bear respectively against the bearing blocks 29 and 29a. The pistons 45 and 45a are springloaded at 47 to initially hold the bearing blocks, Wear plates and gears in contact. During pump operation, however, the pressure of the delivered tiuid is applied to the motive surfaces of 'the pistons 45 and 45a to cause these pistons to so press against the bearing blocks 29 and 29a as to counteract the separating force which the delivered fluid exerts on the various wear plates. As this separating pressure is definitely and consistently concentrated at the delivery side of the pump, due to the grooves 29, the counteracting pressure exerted by the pistons 45 and 45a must be greatest at said delivery side. To attain this, the axes A of the pistons 45 and 45a and their chambers 46 and 46a are offset toward the delivery side of the pump from the centers C as shown in FIGURES 2 and 3. As the grooves 39 provide the wear plates with constant areas against which the delivered fluid consistently exerts pressure tending to separate the Wear plates from the gears, a definite basis is provided upon which to determine the proper piston area to be employed.

In the present disclosure the chambers 46 and 46a are placed in communication with the delivery zone D by connecting said chambers with each other by means of a passage 48 (FIGURES l to 4) in the end closure 13, and by placing said passage 48 in communication with the delivery Zone D by means of registering passages 49, 50 (FIGURE 4) in the end closure 13 and body 11, respectively. An O-ring seal 51 (FIGURE 4) is provided around the meeting ends of the passages 49, 50.

To prevent any accumulation of pressure which might interfere with seating of the bearing blocks 28 and 28a against the end closure 12, a groove 52 (FIGURES l and 4) is formed in the inner side of said end closure 12 and said groove is placed in communication with the uid receiving zone R by means of registering passages 53, 54 in said end closure and the body 11, respectively as seen in FIGURE 4. An O-ring seal 55 is provided around the meeting ends of the passages 53, 54. The blind passage 56 in FIGURE 4 comes into operation only when the body 11 is turned 180 from the position shown, for the purpose above explained. It then registers with the '5 passage 54. An O-ring seal 57 is provided around the outer end of the passage 56.

Two 8shaped O-ring seals 58' peripherally surround the bearing block sets 2.8, 28a and 29, 29a, respectively,

and seal between these blocks and the walls of the bores 23, 23a. The blocks have peripheral grooves or packing chambers 59 in which the seals 5S are seated. Each seal S has an integral cross bar 60 which seals transversely between the blocks 28, 28a or 29, 29a. The abutting surfaces of the blocks are grooved at 61 to receive the cross bar 60. The center of this cross bar 60 has an integral linger 62 which longitudinally seals between the blocks and at its Ifree end abuts the wear plates 33, 33a

l or 35, 35a. The blocks are grooved at 63 to receive the finger 62. Leakage from the delivery side of the pump to the receiving side is thus prevented and also any leakage between the blocks and the walls of the bores 23, 23a is obstructed.

Reference is now made to FIGURE 10 wherein there is shown a modified form of pump housing, generally referred to by the numeral 65. The pump housing 65 is formed of a pump body 66 having an integral end 67. The opposite end of the pump body 66 is closed by the aforementioned end closure 12. Itwill be readily apparent that the pump body 66 with its integral end 67 corresponds to the pump body 11 with the removable end closure 13 secured thereto. By making the pump body 66 and the end 67 integral, the possibility of leakage from the pump housing 10 is restricted to the connection between the pump body 66 and the end closure 12 and the seal between the shaft 18 and the end closure 12.

In FIGURE 10, as well as FIGURES l1 through 13, there is also illustrated a modified form of wear plate 63. The wear plate 68 corresponds generally to the composite wear plate formed by each pair of wear plates 33 and 33a. The wear plate 68 is of a one-piece construction and is specifically shown in FIGURES 11, 12 and 13.'

The wear plate 68 corresponds generally to the outline of the interior of the pump body 66 with the exception of relief notches 69 and 70 formed at opposite sides thereof. The wear plate 68 is also provided with shallow relief notches 71 which extend around generally the delivery side thereof. In addition, the Wear plate 68 is provided with a pair of arcuate' grooves 72 which correspond to the grooves -39 in the wear plates 33 and 33a. It has been found, however, that the groove 4G of'the wear plates '33 and 33a is not Vrequired in that there is sufiicient flow of uid past the teeth of the pumping gears.

The wear plate 68 is provided with a pair of circular openings 73 therethrough which correspond to the openings 38 .and which receive the bearing stubs 42 of the pumping gears. In order to strengthen the wear plate 68, the notch corresponding to the notches 37 hasbeen eliminated. However, sufficient iiow area has been provided inthe wear plate 68 by providing a large relief 74 in the face of the wear plate 68 which opposes the pumping gears.

The formation of the wear plates of a one-piece construction has definite advantages. In the irst place, the wear plates are relatively thin and due to the unequal pressures applied thereagainst, there is a constant tendency for the edges of the wear plates to slide or cock relative to one another with possible slippage of the Wear plates relative to each other when constructed as shown in FIGURE 5. Also, it is much easier to assemble a one-piece wear plate as opposed to a plural wear plate arrangement such as that provided by the wear plates 33 and 33a.

-It has also been found that the pistons 45 and 45a, in directly bearing against the bearing blocks 29 and 29a do not properly distribute the pressures to be exerted on the bearing blocks due to the enlarged opening in the bearing blocks for the reception of the bearings 43 and the bearing stubs 42. Accordingly, vthe end portion 67 of -and 76a are identical and interchangeable.

the pump housing 66 has been recessed to permit the insertion of pressure plates 75 and 75a intermediate the pistons 45 and 45a and the bearing blocks 29 and 29a, respectively, so that a more accurate distribution of the pressure by the pistons 45 and 45a on the bearing blocks 29 and 29a, respectively, may be obtained.

Referring now to IFIGURE 14, it will be seen that there is illustrated another slightly modified yform of pumprin accordance with this invention. The pump shown in FIGURE 14 differs from the pump shown in FIGURE 10 in that in lieu of the bearing blocks 28, 28a, 29 and 29a, there has been provided 'bearing blocks 76 and 76a. The bearing blocks 76 and '76a are of the same general outline as the bearing blocks 29 and 29a, respectively,` and differ therefromin that in lieu of the offset positions of the peripheral grooves or backing chambers 59, the bearing blocks 76 and 76a are provided with peripheral grooves or backing chambers 77 which are centrally located. Also, while the bearing blocks 29 and 29a are provided with only a partial groove 63, the bearing blocks 76 and 76a are provided with longitudinal grooves 78 which extend the full length thereof. The bearing blocks 76 and 76a are otherwise identical with the bearing blocks 29 and 29a, respectively, and the changes in the positions in the grooves in the bearing blocks will become obvious hereinafter.

Referring now to FIGURE 15 in particular, it will be seen that there is illustrated an 8-shaped O-ring seal, generally referred to by the numeral 79, and corresponding generally to the seal 53. The seal 79 includes two generally circular portions Sti which are connected together by an integral cross-bar S1. The cross-bar S1 has extending from opposite faces thereof at its center a pair of fingers 82. The fingers 82 are in alignment and extend normal to the general plane of the seal 79. IIt is to be noted that the ngers 82 are received in the grooves 78.

It will be readily apparent that the bearing blocks 76 When it is desired to assemble a pair of bearing blocks and a seal 79 into the pump body 66, it is merely necessary to indiscriminately pick up a pair of sealing blocks and slip them linto the seal 79, as is shown inF-IGURE 16. At this time the generally circular portions 86 of the seal 79 are seated in the grooves 77 and the lingers 82 are seated in the opposed grooves 73. At the same time,'the cross-bar 81 is seated in opposed grooves 83 which extend transversely of the flat surfaces of the bearing blocks 76 and 76a and which intersect the grooves 78.

The bearing block and seal assembly of FIGURE 16, which is generally referred to by the numeral 84, may then be indiscriminately positioned within the pump body 66. It will be readily apparent that it is immaterial as to which of the bearing blocks is disposed uppermost although the uppermost bearing block is referred to by the numeral 76, and the lowermost bearing block is referred to by the numeral 76a. which faces of the bearing blocks' are first passed into the pump body 66. Thus, it will be readily apparent that by centering the grooves 77 and 83 and by extending the grooves 78 the full longitudinal length of'the bearing blocks, there can result an interchangeable bearing block construction of the type wherein only one kind of bearing block need be supplied and this bearing block may be indiscriminately assembled with the seal 79. Further, the bearing block and seal assembly 84 may be indiscriminately positioned within the pump body 76.

' From the foregoing, it will be seen that a novel and i advantageous construction has been disclosed for attaining the desired ends. However, attention is again invited to the possibility of making variations within the scope of the invention.

We claim:

1.' In a gear pump, .a housing having two cylindrical bores with intersect at a median plane, and end closures Further,- it is immaterial as to for the ends of said bores, a first set of two bearing blocks within one end portion of said bores and abutting one of said end closures, said two bearing blocks of said first set having at surfaces abutting at said median plane, a second set of two bearing blocks within the other end portion of `said bores adjacent the other of said end closures, said two bearing blocks of said second set having flat surfaces abutting at said median plane, two meshed gears between said first and said second sets of bearing block-s and having bearing stubs mounted in said two sets of blocks, said gears being operative to pump fluid from a receiving zone in said housing to a delivery zone therein, wear plates interposed between the side faces of said gears and the inner faces of said sets of bearing blocks and contacting with all of these faces, two pistons abutting the outer sides of the two bearing blocks respectively of said second set, said other of said end closures having chambers in which `said pistons are slidable, means for conducting uid pressure from said delivery zone to the motive sur-faces of said pistons to cause these pistons to hold the bearing blocks, wear plates and gears in contact with each other, and means communicating with said receiving zone and serving to prevent trapping of pressure between the bearing blocks of said first set and said one of said end closures, said wear plates being in the form of two sets of wear plates with said Wear plates contacting respectively with the four bearing blocks, said wear plates of each set of wear plates having straight edges abutting at said median plane.

2. In a gear pump, a housing having two cylindrical bores which intersect at a median plane, and end closures for the ends of said bores, a iirst set of two bearing blocks within one end portion of said bores and abutting one of said end closures, said two bearing blocks of said iirst set having iiat surfaces abutting at said median plane, a second set of two bearing blocks within the other end portion of `said bores adjacent the other of said end closures, said two bearing blocks of said second set having fiat `surfaces abutting at said median plane, two meshed gears between said first and second sets of bearing blocks and having bearing stubs mounted in said two sets of blocks, said gears being operative to pump iluid from a receiving zone in said housing to a delivery zone therein, wear plates interposed between the side faces of said `gears and the inner faces of said sets of bearing blocks and contacting with all of these faces, two pistons abutting the outer sides of the two bearing blocks respectively of said second set, said other of said end closures having chambers in which said pistons are slidable, means for conducting iiuid pressure from said delivery zone to the motive surfaces of said pistons to cause these -pistons to hold the bearing blocks, wear plates and gears in contact with each other, and means communicating with said receiving zone and serving to prevent trapping of pressure between the bearing blocks of said first set and said one of said end closures, said Wear plates having arcuate grooves spanned by the teeth of said gears, each of said grooves being formed only in a gear opposing face of its respective wear plate and extending from a point between said receiving and delivery zones substantially to the meshing zone of said gears with said arcuate grooves in communication with said delivery zone, thereby causing the pressure of delivered uid to exert consistent outward pressure on the portions of said wear plates at the delivery side of the pump, said pistons being arranged to counteract said pressure.

3. In a gear pump, a housing having two cylindrical bores which intersect at a median plane, and end closures for the ends of said bores, a first set of two bearing blocks within one end portion of said bores and abutting one of said end closures, said two bearing blocks of said rst set having flat surfaces abutting at said median plane, a second set of two bearing blocks within the other end portion of said bores adjacent the other of said end closures, `said two bearing blocks of said second set having fiat `surfaces abutting -at said median plane, two meshed gears between said first and second sets of bearing blocks and having bearing stubs mounted in said two sets of blocks, said gears being operative to pump iiuid from a receiving zone in said housing to a delivery zone therein, wear plates interposed between the side faces of said `gears and the inner faces of said sets of bearing blocks and contacting with all of these faces, two 8- shaped O-ring vseals peripherally surrounding the first and second sets of bearing blocks .respectively and sealing between said bearing blocks and the walls of said bores, each of said S-shaped O-ring seals having an integral cross bar extending from one side to the other of the respective O-ring and `sealing transversely of the axes of said bores between said flat abutting surfaces of the blocks, each of `said cross bars having an integral finger extending toward said gears and sealing longitudinally of the bore axes between said tiat abutting surfaces of the blocks, the free ends of the two lingers abutting the outer sides of said wear plates.

4. In a gear pump having two cylindrical bores intersecting at a median plane, a set of two bearing blocks in said bores and having flat lsurfaces abutting at said median plane, wear plate means contacting the inner sides of said bearing blocks, and meshed gears contacting with said wear plates means and having bearing stubs mounted in said bearing block-s; an S-Shaped O-ring seal peripherally surrounding said set of blocks and sealing between said blocks and the walls of said bores, said S-shaped @-ring seal having an integral cross bar extending from one side of the other of said O-ring sealing transversely of the axes of said bores between said flat abutting surfaces of said blocks, said cross bar having an integral finger extending toward said gears and sealing longitudinally of t-he bore axes between said tiat abutting surfaces of said blocks, the free end of said finger abutting the outer side of said wear plate means.

`5. An -shaped O-ring seal to peripherally seal between a set of two bearing blocks which abut at a median plane and each bearing block having a bearing axis disposed parallel to said median plane, said S-shaped O-ring seal having an integral cross bar extending from one side to the other of said O-ring to transversely seal between the abutting surfaces of the blocks relative to said bearing block axes, said cross bar having an integral finger to longitudinally seal between said `abutting surfaces relative to said bearing block axes.

6. The S-shaped O-ring seal of claim 5 wherein said integral .fin-ger extends to opposite sides of said cross bar.

7. In a gear pump, a housing having two cylindrical bores which intersect at a. median plane, and end closures for the ends of said bores, a -iirst set of two bearing blocks within one end portion of said bores and abutting one of said end closures, said two bearing blocks of said first set having at surfaces abutting at said median plane, a second set of two bearing blocks within the other end portion of said bores adjacent the other of said end closures, said two bearing blocks of said second set having fiat surfaces abutting at said median plane, two meshed Igears between said tirst and second sets of bearing blocks having bearing stubs mounted in said two sets of bearing blocks, said `gears being operative to pump fluid from a receiving zone in said housing to a delivery zone in said housing, wear plates interposed between the side faces of said gears andthe inner faces of said sets of bearing blocks and contacting with all of these faces, each of said wear plates having an arcuate groove formed therein and which opens through the `face of the respective wear plate disposed in opposed relation to a respective one of said gears, said arcuate grooves being disposed substantially concentric with respective ones of said gears and extending between a point substantially midway between said receiving and delivery zones substantially to the meshing zone of said gears with said arcuate grooves being radially spanned 9 by the teeth of respective ones of said gears with said arcuate grooves in communication with said delivery zone to cause the pressure of the delivered uid to constantly exert an outward force on the portions of said we-ar plates at the delivery lside of the pump tending to separate said wear plates from said gears, two pistons abutting the outer sides of the two bearing blocks respectively of said second set of bearing blocks, said other of said end closures having chambers in which said pistons are slidably mounted, means for conducting fluid pressure from said delivery zone to the motive surfaces of said pistons to cause these pistons to hold said bearing blocks, wear plates and gears in contact with each other and counteracting the separating pressure of said delivery fluid on said wear plates, and means communicating with said receiving zone and serving to prevent trapping of pres-- sure between the bearing blocks of said first set of bearing blocks and said one of said end closures.

8. A `bearing block Iand sealing ring assembly for mounting as a unit within a housing comprising a set of two bearing blocks which abut at a median plane, each of said bearing blocks having a continuous groove in the peripheral surface thereof including that portion which extends along the median plane, and an 8-shaped sealing ring, said sealing rin-g including -an integral crossbar extending from one side to the other of said ring, said se-aling ring being disposed in each peripheral groove of said two bearing blocks with said cross-bar being disposed along said median plane land sealing said bearing blocks relative to each other along said median plane, said sealing 4ring projecting outwardly of the peripheral surfaces of said bearing blocks for sealing engagement with a housing.

9. In the assembly of claim 8, said bearing blocks having longitudinal grooves extending the full length thereof, and said sealing rin-g having an integral finger extending to opposite sides of said cross bar and being seatable in said longitudinal grooves whereby orientation of said bearing blocks and said O-ring seal is eliminated.

10. -A gear pump comprising a housing containing a pair of meshing rotary gears each having a bearing stub, -a pair of bearing 'blocks for the stubs having abutting diat surfaces and peripheral surfaces, a peripheral packing chamber formed in the peripheral surfaces of said bearing blocks, a recess extending transversely of the axes of the bearing stubs and between said surfaces formed by mating recessing in the abutting surfaces, said recess connecting opposi-te sides of said packing chamber, and a figure 8-shaped sealing ring in said chamber and recess for sealing said bear-ing blocks with respect to said housing and with respect to each other.

I11. A gear pump in accordance with cla-im 10 in which said packing chamber has side walls closely confining said sealing ring.

412. A gear pump in accordance with claim 10 in which there is a recess extending longitudinally of said bearing stub axes between said abutting surfaces and intersecting said transverse recess, and said sealing ring includes a finger portion integral therewith and within said longitudinal recess.

1'3. A gear pump in accordance with claim 12 in which Y Within one end portion of said bores and abutting one of 10 adjacent ends of the gear tooth pockets, means adjacent each said block and separate therefrom for moving each said block toward said gear, each of said gears having a 'face disposed transversely of the axes thereof and extending between the bottoms of the tooth pockets and the associated stub, each of said blocks having a portion opposite said transverse face for transmitting thrust directly toward said face, and anti-friction bearing elements in direct rolling contact with both said stub and said block.

16. A gear pump according to claim 15 in which a one-piece wear plate. member is interposed between said gears and the two bearing blocks at each face of said gears for transmitting thrust from said bearing blocks to said gear faces.

17. A gear pump in accordance with claim 15 in which a separate Wear plate member is interposed between each said 'block and said gear, each said wear plate extending opposite a respective said block portion for transmitting thru-st therefrom directly to a respective said face.

18.` A gear pump in accordance with claim 17 in which each said wear plate member includes a portion extending radially inward toward the axis of the gear stub surrounded by the associated block portion a distance for closely approximating the bearing elements contacting diameter of the respective gear 'stub and for providing additional area of contact with the opposing gear for closing the respective gear tooth pockets.

19. A pump in accordance with claim 15 wherein each bearing block includes means for limiting movement of respective ones of said anti-friction bearing elements in at least one direction longitudinally of the axis of the respective bearing stub.

20. A pump in accordance with claim 15 wherein each bearing block Ahas an internal face adjacent the respective gear defining a stub receiving bore, and said internal face is recessed for receiving saidV anti-friction bearing ele-v ments.

21. In a gear pump, a housing having two cylindrical said end closures, said two bearing blocks of said first set having flat surfaces abutting at said median plane, a second set of two bearing blocks within the other end portion of said bores adjacent the' other of said vencl closures, said two bearing blocks of said second set having flat surfaces abutting at said median plane, each of said bearing blocks of each of said sets of bearing blocks having a continuous groove in the peripheral surface thereof including that portion which extends along the median plane, two S-shaped sealing rings each having an integral cross-bar extending from one side to the other of the respective ring, each sealing ring being disposed in each peripheral groove of the two bearing blocks of each set of bearing blocks with said cross-bar being disposed along said median plane, each sealing ring serving to interlock the two bearing blocks of each set of bearing blocks and to seal the same with respect to each other and said housing while permitting limited movement of said longitudinal and transverse recesses comprise corn- A 'from each of the gears, an individual bearing block surrounding each of said stubs and movable within the housing toward the respective gear for effecting closure of the each bearing block, two meshed gears between said first and second sets of bearing blocks having bearing stubs mounted in said two sets of bearing blocks, bearing elements seated within each of said bearing blocks and supporting a respective one of said bearing stubs -for rotation, each of said bearing blocks having a recess receiving its respective bearing elements to thereby restrain the longitudinal movement of said bearing elements, said gears being operative to pump fluid from a receiving zone in said housing to a delivery Zone in said housing, Wear plates interposed between the side faces of said gears and the inner faces of :said set-s of bearing blocks and contacting with all of these faces, two pistons abutting the outer sides of the two bearing blocks respectively of said second set of bearing blocks, said other of said end closures having chambers in which said pistons are slidably mounted, means for conducting fluid pressure from said delivery zone to the motive surfaces of said pistons to cause these pistons to hold `said bearing blocks, Wear plates and gears in contact with each other, while permitting individual movement of said bearing blocks.

22. The pump of claims 21 wherein each sealing ring has a nger integral with the cross-bar thereof, each finger extending towards said gears and sealing longitudinally between abutting surfaces of the two bearing blocks of each of said sets of bearing blocks, and the free end of each of said fingers abutting the outer faces of adjacent ones of said wear plates.

23. A structure as specified in claim 21 in which said Wear plates have arcuate grooves spanned by the teeth of said gears, each of said grooves being formed only in a gear opposing face of its respective wear plate and extending from a point between said receiving and delivery zones substantially to the meshing zone of said gears with said arcuate grooves in communications with said delivery zone, thereby causing the pressure of delivered fluid to exert consistent outward pressure on the portions of said wear plates at the delivery side of the pump, said pistons being arranged to counteract said pressure.

24. An 8-shaped O-ring seal to peripherally seal between a set of two bearing blocks which abut at a median plane, said S-shaped O-ring seal having an integral crossbar to transversely seal between abutting surfaces of the blocks, and said cross-bar having integral fingers extending in alignment from opposite faces thereof and normal to the general plane of said -shaped O-ring seal whereby said seal may be indiscriminately mounted.

2S. In a gear pump, a set of two bearing blocks which abut at a median plane, each bearing block being generally cylindrical except for a at surface adapted for abutment with a like flat surface of another of said bearing blocks along the median plane, a seal receiving peripheral groove in each bearing block at the longitudinal center thereof, and a transversely centered seal receiving groove extending longitudinally in `said at surface and intersecting said peripheral groove whereby orientation of said bearing blocks is eliminated,

26. In a gear pump, a housing having opposed ends, a set of bearing blocks within said housing adjacent each end, one set of bearing blocks being seated against one housing end, a pair of pumping gears joumalled between said bearing blocks, wear plates disposed between said sets of bearing blocks and said pumping gears in contacting relation therewith, vsaid other housing end having cylinder-like recesses therein receiving fluid under pressure, a piston in each cylinder-like recess, and a separate pressure plate disposed between each piston and an adjacent bearing block for transmitting the forces exerted by said pistons to said bearing blocks adjacent said other housing end whereby all of said bearing blocks, said wear plates and said pump gears are urged towards said one housing end.

` References Cited by the Examiner UNITED STATES PATENTS 2,082,412 6/ 1937 Morton.

2,624,287 1/1953 Ilyin 103-126 2,649,740 8/1953 Murray et al. 103-126 2,682,836 7/1954 Orr 103-126 2,728,301 12/1955 Lindberg 103-126 2,756,681 7/1956 Oliver 103-126 2,816,512 12/1957 Murray 103-126 2,864,315 12/1958 Uda'le 103-126 2,865,302 12/1958 Murray 103--126 2,876,705 3/ 1959 Aspelin et al. 103-126 2,881,704 4/1959 Murray 103-126 2,891,483 6/1959 Murray et al. 103-126 2,932,254 4/1960 Booth et al. 103--126 2,969,744 1/ 1961 Hofer 103-126 2,974,605 3/1961 Murray 103-126 2,980,028 4/ 1961 Edwards et al. 103-126 2,981,200 4/1961 Stephens 103-126 2,982,220 5/1961 Kane 103--126 2,993,450 7/1961 Weigert 103-126 3,057,302 10/1962 Lockett 103-126 3,063,378 11/1962 Hart 103-126 3,083,645 4/1963 Donner et al. 103-126 FOREIGN PATENTS 536,036 11/1955 Italy.

1,060,496 11/ 1953 France. 1,073,038 3/ 1954 France. 1,121,180 4/1956 France.

d DONLEY J. STOCKING, Primary Examiner.

WILBUR J. GOODLIN, JOSEPH H. BRANSON, IR.,

KARL I. ALBRECHT, Examiners. 

1. IN A GEAR PUMP, A HOUSING HAVING TWO CYLINDRICAL BORES WITH INTERSECT AT A MEDIAN PLANE, AND END CLOSURES FOR THE ENDS OF SAID BORES, A FIRST SET OF TWO BEARING BLOCKS WITHIN ONE END PORTION OF SAID BORES AND ABUTTING ONE OF SAID END CLOSURES, SAID TWO BEARING BLOCKS OF SAID FIRST SET HAVING FLAT SURFACES ABUTTING AT SAID MEDIAN PLANE, A SECOND SET OF TWO BEARING BLOCKS WITHIN THE OTHER END PORTION OF SAID BORES ADJACENT THE OTHER OF SAID END CLOSURES, SAID TWO BEARING BLOCKS OF SAID SECONDS SET HAVING FLAT SURFACES ABUTTING AT SAID MEDIAN PLANE, TWO MESHED GEARS BETWEEN SAID FIRST AND SECOND SETS OF BEARING BLOCKS AND HAVING BEARIN STUBS MOUNTED IN SAID TWO SETS OF BLOCKS, SAID GEARS BEING OPERATIVE TO PUMP FLUID FROM A RECEIVING ZONE IN SAID HOUSING TO A DELIVERY ZONE THEREIN, WEAR PLATES INTERPOSED BETWEEN THE SIDE FACES OF SAID GEARS AND THE INNER FACES OF SAID SETS OF BEARING BLOCKS AND CONTACTING WITH ALL OF THESE FACES, TWO PISTONS ABUTTING THE OUTER SIDES OF THE TWO BEARING BLOCKS RESPECTIVELY OF SAID SECOND SET, SAID OTHER OF SAID END CLOSURES HAVING CHAMBERS IN WHICH SAID PISTONS ARE SLIDABLE, MEANS FOR CONDUCTING FLUID PRESSURE FROM SAID DELIVERY ZONE TO THE MOTIVE SURFACES OF SAID PISTONS TO CAUSE THESE PISTONS TO HOLD THE BEARING BLOCKS, WEAR PLATES AND GEARS IN CONTACT WITH EACH OTHER, AND MEANS COMMUNICATING WITH SAID RECEIVING ZONE AND SERVING TO PREVENT TRAPPING OF PRESSURE BETWEEN THE BEARING BLOCKS OF SAID FIRST SET AND SAID ONE OF SAID END CLOSURES, SAID WEAR PLATES BEING IN THE FORM OF TWO SETS OF WEAR PLATES WITH SAID WEAR PLATES CONTACTING RESPECTIVELY WITH THE FOUR BEARING BLOCKS, SAID WEAR PLATES OF EACH SET OF WEAR PLATES HAVING STRAIGHT EDGES ABUTTING AT SAID MEDIAN PLANE. 